Telephone-exchange system.



R. D. CONWAY.

TELEPHONE EXCHANGE SYSTEM.

APPLICATION FILED MAR. 2|. 19w.

1 ,272,624. Patented July 16, 1918.

III

. I T i -..-.l l lm/enforz Roy D. Conway y 'Affy ROY D. CONWAY, F CHATHAM, NEW JERSEY, ASSIGNOR T0 WESTERN ELECTRIC COM- PANY, INCORPORATED, OF YORK, N. Y., A CORPORATION OF NEW YORK:

TELEPHONE-EXCHANGE SYSTEM.

Specification of Letters Patent.

Application filed March 21, 191?-v Serial No. 156,294.

. circuit, employed in interconnecting subscribers lines for conversation, is provided with apparatus by means of which ringing on a called line starts almost immediately upon the connection of the link circuit therewith. The link circuit is also provided with motor mechanism, preferably in thefo m of a step-by-step actuated electromagnet, for controlling the period of ringing, that is, the duration of the ringing and silent intervals. V 1 j This invention, in one embodiment, is

illustrated in the accompanying drawing, in I which there are telephone lines A and B, terminating at central oflice, and a link circuit C thereat for interconnecting these lines; It is believed that this invention will be fully understood from a description of the operation of the system shown in the drawing, and it will'beso described.

'The operatonafter being informed ,by the subscriber of telephone line A connected with cordcircuit C (in any desired manner), that connection with line B is desired,"inserts calling plug 5 intojjack 6 of line B,-

whereupon relay Tand cutoff relay 8oper-.

ate, and a calling supervisory lamp'Qflights over a circuit from battery through lamp'9, winding of relay 7, sleeve con'tactsof plug 5 and jack 6, and the win'ding of cutoffire lay 8 to ground. -Upon the operation of relay 7, ringing rel'a'y 10 operatesover a circuit frombattery through the winding of relay 10,,normal contacts of relay '11 and tripping relay 12,and contact of relay 7 to ground. Relay lQ, in operating, opensfup the tip and'r'ing strands of the cord'circuit, and at the sametime connects the tip of the plug through to ground and the ring thereof with the winding of the tripping relay 12. Relay 10, in operating also causes the operation of start relay over a circuit from battery through brush 16, segment 17 of commutator 18, winding of relay 15, contact 19 thereof, and the middle alternate contactof relay 10 to ground. Relay 15, in operating, serves. as a switching device to connecta source of. signaling current to line B over a path from the source of signaling current through the right-hand alternate contact of relay 15, winding of tripping relay 12, lower alternate ringing relay 10, ring contacts of the plug 5 and jack 6, over one side of the line, through the call bell-and condenser at the substation, back over the other side of the line, tip contacts of the jack 6 and plug 5, upper alternate contact of relay 7, and upper alternate contact of relay 10 to ground. The relay 15, in operating, also completes a lockingcircuit' for'itseli' through its contact 26, this locking circuit including the brush 16 and the segment 17 of'the commutator 18. The operation-of start relay 15 also completes an operating circuit for motor magnet 30, which may be traced from battery through left hand alternate contact of relay 15, winding of motor magnet 30, and interrupter 31 to ground. Motor magnet is thereupon intermittently actuated, attracting its armature'32 to cause pawl 33, connected therewith, to engage a tooth of a ratchet wheel 34, secured to shaft 35 upon which the commutator 18 is mounted. The successive energization of motor magnet 30' causes, "through the pawl 33 and the ratchet wheel 34, successive one-step advancements of the commutator 18 in the direction indicated by the'arrow. .When thecommutator has rotated a distance equivalent to the length of the segment 17, the brush 16 passes off of segment17 on to'segment 40. "As contact is brokenbetween brush 16 and segment 17, the locking [circuit of relay 15 is broken, whereupon this relay releases and opens the fhere'in'before traced operating circuit for the motor magnet 30. However, when the brush Patented July 16, 1918.

moves on to segment 40, whereupon a second operating circuitfor the motor: magnet s substituted forj the first This second cirunit may be traced from battery through brush l6, segment 40 of commutator 1S,- winding of motor magnet 30 and interrupter 31 to ground Upon-the removalof the receiver from theswitchhook by. subscriber B, tripping relay 12 is operated, thereupon removing the short circuit of relay 11, which: then operates and locks up. The operation.

oh relay'll short-circuitsrelay 1O;1V\"-l1i'(3l1 1 6- leases, removing ringing current from the called line, and closing the breaks in the talkingstrands of the cord circuit. Immediately upon the release of" relay 1'0, super-' visory relay 4-1 isoperated to connect a shunt circuit, including resistance 42, about thecaliing supervisory lamp 9; whereupon this lamp is effaced,

H the called surhscriber removes his re ceiver from the switchhook before the commutator 18 has made a complete revolution, the commutator will continue its movement until the brush has again reached't'he' normal position indicated in the drawing. Since ringingrelay l0'is now released, the initial energizing circuit for start relay 151s open, and'the commutatorand motor magnet associated therewith remain inactive; It; When the commutator reaches its normal position, ringing relay 10 is still operated, the initial energizing circuit forrelay 15 will again be closed, thereby starting the second'rotation oh the commutator; V

i From the above, itwill' be seen that in a system utilizing the present invention, ring:- i'ng upon the called line startsalinost immediately" upon the insertion of theicallingplu of. the cord circuit into the jack of that line. It will furthermore be seen that the, present invention provides a comparatively short ringing interval, followedby a comparatively long'interval' in which ringing current is not connected to the line, a n'd' tha t when once started; the commutator always makes a complete revolution. v is claimed is; a

a 1. A telephone exchange system comprising telephone lines, a link circuit, a source of signaling current, a commutator, an, electromagnetic switchingdevic'e forconnecting signaling current to a line and operating under theontrol of the commutatorin response to tlieconn'ection of; the link circuit with. a line, and motor mechanism for actuating the commutator started, upon the operation of the.electromagnetic SYVllZGhlllgflGVlCO. i

J .2. "A- telephone: exchange system comprising'telephone lines, alinkcircuit,a sourceof signaling current, a commutator, an electromagnetic switching device for connecting signaling currentto a line, an operating circuit thereforiincluding the commutator, com- 7 pletedr in response to the connection oit' the link-circuit with a line and motor mechanism for actuating the commutator started upon the operation of the electromagnetic switching device; 7 7

r 3. A telephone exchange system comprising telephone lines, alink circuit, asource o f signaling current, a rotatable commutator adapted when started to make a complete revolution-,.an electromagnetic switching device operating under control of the commutator when-the link circuit is connected with a line to connect signaling current therewith and released when the commutator has retated a predetermined distance, motor mech:

anism for rotating the commutator; an op"- cuit therefor incliiding the commutator es;

tabl-ished upon" the connection ofthe link circuit with a line and maintained until the commutator has rotated" a predetermined distance, motor mechanism for rotating the commutator, air operating' circuit for the motor mechanism inclu'din'ga contact of'the switching"device, anda secondoperating circuit" for the motormechanism substituted for the first mentioned operating circuit'when the commutator has rotated I a predetermined distance. 7 v

- 5-. A telephone exchangesy'steincomprisingitelephone lines, a link circuit,,a-source of signaling current, a step-by-step actuated commutator, an electromagnetic switching device forconnecti'ng signaling current to a line, an operating circuit therefor including the commutator. completed in response tothe connection of'thelink circuit with a line, an intermittently actuated; motor magnet for actuating the, commutator, and? an operating circuit for themotoi: magnet completed upon the operation of theswi'tehing device.

t G'QA telephone exchange system compli sing-telephone lines, a linkcircuit, a source of signa ling current, a rotatable! commutator adapted when s-tarted' to make a complete revolution, an.electromagnetic switching de- 7 with a line and. maintained until tlieeommutato'rvhas rotated a predetermined distance, an intermittently actuated motor magnetfor imparting: sep-by-step movement to the com- 7 mutat'or, and an operating circuit for the vnecting signaling current to the line operating under the control of the commutator, motor mechanism for actuating the commutator, and means controlled by said switching means for starting said motor mechanism into operation.

In witness whereof, I hereunto subscribe my name this 20th day of March A, 1)., 1917 ROY D. CONWAY.

motor magnet established by the operation of the electromagnetic switching mechanism and maintained by the commutator after the rotation thereof for the predetermined distance.

7. In a telephone exchange system comprising telephone lines, a link circuit, a source of signaling current, a commutator, an electromagnetic switching device for conbe obtained for live cents each, by addressing the "Commissioner of Patents,

Washington, D. 0."

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